Improvement in mill-stone dressings



UNITED STATES HENRY DOLMETOH, OF CANTON, PENNSYLVANIA.

IMPROVEMENT IN MILL-STONE DRESSINGS.

Specification forming part of Letters Patent No. 120,505, dated October 31, 1871.

To all whom t may concern:

Be it known that I, HENRY DoLMETcE, of Canton, in the county of Bradford and State of Pennsylvania, have invented a new and valuable- Improvement in Mill-Stone Dress and I do hereby declare that the following is a full, clear, and exact description of the construction and op eration of the same, reference being had to the annexed drawing making a part of this specification, and to the letters and iigures of reference marked thereon.

Figure l of the drawing is a plan view of my dress. Fig. 2 is a plan view, showing a modification thereof. Fig. 3 is a side view. Fig. 4 is a sectional view of the Lipper stone reversed.

My invention relates to mill-stone dress, and consists in the novel shape and arrangement of the grinding-furrows in the surfaces of the bedstone and runner, whereby advantageous results are produced.

A ofthe drawing represents the bed-stone. B is the runner moving thereon, and provided with the central circularI opening or recess G. Extending outward from the central circular recess C are the grinding furrows c. Joining each main furrow c, near its junction with the recess O, is a branch furrow, d, similar in every respect except in length. Each furrow has two bounding walls, one, a, perpendicular, and the other, a', oblique to the face of the stone. The direction of the perpendicular wall of each main channel is tangential to the circular wall of the recess O, at its junction therewith. The channel has the same direction for about two-thirds the distance from the center ofthe stone to its perimeter. At this point it deviates from the right line, and, gradually curving toward the parallel radius, iinishes the remaining third of its length. Gr Gr are the scraper-s, attached to the side of the runner, and designed to keep the outlets of the channels free. H represents the discharge-opening.

The operation of my dress is very satisfactory. On account of the oblique position of the channels and the perpendicular distance of their inner ends from the center of motion the grinding is rapid, even at the beginning of the channel; but lest some of the coarser particles should iind their way out, the motion of the grain in the channels is gently retarded by the curved portion thereof. As the relative velocity of this outer portion of the channel is the greatest its action is most efficient, and the comminuted matter is thoroughly pulverized thereby. In order to reap the full beneiit of my dress, the egress of the ground particles must be retarded by nothing but the curve of the channels; hence the necessity of the Scrapers. They are usually of leather, and their ends extend downward a short distance over -the edge of the bed-stone, the outer ledge lc being depressed for this purpose. Sometimes several parallel branches are joined to the main channel.

What I claim as my invention, and desire to secure by Letters Patent, is`

1. The mill-stone dress herein described, its V-shaped channels having their inner straight portions tangential to the eye but oblique to the radins, and their outer portions curved, as specied.

2. In combination, the runner B having the dress herein described, and the scrapers and the bed-stone A having a similar dress, and the depressed ledge k, as specified.

In testimony that I claim the above I have hereunto subscribed my name in the presence of Witnesses SAMUEL BENEDIGT,

HENRY J. BENEDICT. (57) 

